Keith,
I've had good luck removing broken studs from exhaust manifolds with
this method (assuming there is at least 1/4 inch sticking out).
The reason the studs seize in the manifold is due to rust on the
threads, which of course develops from condensation. What you need to do to
is shatter the rust, which as it happens, is not to difficult because rust is
a brittle intermetallic.
You can break the rust by heating the metal, since Fe has a much
higher coefficient of thermal expansion than rust, or by smacking the
stud good and hard with a hammer, since rust is very brittle. Some
people do both at the same time.
After you feel that the rust has been broken up, file the sides of
the stud a bit so the VISE-GRIPS don't just slip off. Fit the
VISE-GRIPS, and try to turn the stud in the loosening direction. It
sometimes helps to smack the top of the stud while you're attempting
turning. The instant that you feel turning occurring, stop and twist the
stud the other way. Working the studs out by back-and-forth motion
usually gets them out without breaking. Just remember that getting the
stud loose is not the difficult part. The difficult part is keeping the
stud from breaking while twisting it out of the hole.
Good luck,
Greg
Greg Meboe meboe@wsunix.wsu.edu
Web site>> http://www.scs.wsu.edu/~meboe
Dept. of Mechanical and Materials Engineering
Washington State University, Pullman, Wa.
'85 XJ-12 H.E. (daily) '67 Spit-6 '74 TR-6
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